Edge protector for roof drill bit cutting insert

Abstract

A rotary drill bit includes an elongate drill bit body having a slot at a forward end, an edge protector received in the slot of the drill bit body and a cutting insert having a cutting edge. The edge protector includes: a first side having a first bottom edge and a first top edge; a second side opposed to the first side, the second side having a second bottom edge and a second top edge; and a bottom portion adjoining the first bottom edge of the first side and the second bottom edge of the second side. The cutting insert is received in the edge protector such that the cutting edge is recessed below one of the first top edge of the first side or the second top edge of the second side.

What is claimed is: 
     
         1 . A rotary drill bit for engaging an earth strata material, the rotary drill bit comprising:
 an elongate drill bit body having an axial forward end and an axial rearward end, the drill bit body containing a slot at the forward end;   an edge protector received in the slot of the drill bit body, the edge protector comprising:
 a first side having a first bottom edge and a first top edge; 
 a second side opposed to the first side, the second side having a second bottom edge and a second top edge; and 
 a bottom portion adjoining the first bottom edge of the first side and the second bottom edge of the second side; and 
   a cutting insert having an elongate insert body rotatable about a central axis, the elongate insert body having a pair of symmetrical halves symmetrical about the central axis, each symmetrical half comprising:
 a leading face; 
 a top surface; and 
 a cutting edge formed between the leading face and the top surface, 
   wherein the cutting insert is received in the edge protector such that the cutting edge is recessed below one of the first top edge of the first side or the second top edge of the second side.   
     
     
         2 . The rotary drill bit of  claim 1 , wherein the cutting edge is recessed below one of the first top edge or the second top edge a distance of about 0.001 inches to about 0.050 inches. 
     
     
         3 . The rotary drill bit of  claim 2 , wherein the cutting edge is parallel to one of the first top edge or the second top edge. 
     
     
         4 . The rotary drill bit of  claim 1 , wherein the first side, the second side and the bottom portion each include a plurality of perforations formed therein. 
     
     
         5 . The rotary drill bit of  claim 1 , wherein the edge protector is formed of a material having a hardness value that is less than a hardness value of the cutting insert. 
     
     
         6 . The rotary drill bit of  claim 1 , wherein the edge protector is formed of at least one of copper, steel, aluminum, brass, triclad, or any iron based material. 
     
     
         7 . The rotary drill bit of  claim 1 , wherein the edge protector is affixed to the slot of the drill bit body. 
     
     
         8 . The rotary drill bit of  claim 7 , wherein the cutting insert is affixed to the edge protector. 
     
     
         9 . An edge protector assembly for a rotary drill bit, the edge protector assembly comprising:
 a shim having a first side having a first bottom edge and a first top edge, a second side having a second bottom edge and a second top edge, and a bottom portion adjoining the first bottom edge of the first side and the second bottom edge of the second side; and   a cutting insert having a leading face, a top surface, and a cutting edge formed between the leading face and the top surface,   wherein the cutting insert is received in the shim such that the cutting edge is recessed below one of the first top edge of the first side or the second top edge of the second side.   
     
     
         10 . The edge protector assembly of  claim 9 , wherein the cutting edge is recessed below one of the first top edge or the second top edge a distance of about 0.001 inches to about 0.050 inches. 
     
     
         11 . The edge protector assembly of  claim 10 , wherein the cutting edge is parallel to one of the first top edge or the second top edge. 
     
     
         12 . The edge protector assembly of  claim 9 , wherein the first side, second side and bottom portion each include a plurality of perforations formed therein. 
     
     
         13 . The edge protector assembly of  claim 9 , wherein the shim is formed of a material having a hardness value that is less than a hardness value of the cutting insert. 
     
     
         14 . The edge protector assembly of  claim 9 , wherein the shim is formed of at least one of copper, steel, aluminum, brass, triclad, or any iron based material. 
     
     
         15 . The edge protector assembly of  claim 9 , wherein the cutting insert is affixed to the shim. 
     
     
         16 . An edge protector for a roof drill bit cutting insert having at least one cutting edge, the edge protector comprising:
 a first side having a first bottom edge and a first top edge;   a second side having a second bottom edge and a second top edge;   a bottom portion adjoining the first bottom edge of the first side and the second bottom edge of the second side,   wherein the first side, the second side and the bottom portion are configured for receiving the cutting insert such that the at least one cutting edge is recessed below the first top edge of the first side or recessed below the second top edge of the second side.   
     
     
         17 . The edge protector of  claim 16 , wherein one of the first top edge or the second top edge is parallel to the at least one cutting edge of the cutting insert. 
     
     
         18 . The edge protector of  claim 16 , wherein the first side, second side and bottom portion each include a plurality of perforations formed therein. 
     
     
         19 . The edge protector of  claim 16 , wherein the edge protector is formed of a material having a hardness value that is less than a hardness value of the cutting insert. 
     
     
         20 . The edge protector of  claim 16 , wherein the edge protector is formed of at least one of copper, steel, aluminum, brass, triclad, or any iron based material.